PBS Space Time

Science and Nature Series / 11 Seasons

PBS Space Time explores the outer reaches of space, the craziness of astrophysics, the possibilities of sci-fi, and anything else you can think of beyond Planet Earth. Host Matt O'Dowd breaks down both the basic and incredibly complex sides of space and time.

5m 57s

The New Science of Moon Formation

S9 E1 / 15m 32s

Einstein once asked whether “the moon exists only when I look at it?". It was rhetorical objection to the idea that measurement in quantum mechanics causes reality to become real. But there was a time when the moon didn’t exist, and then hours later suddenly did. At least, according to the latest simulations of its formation.

What If The Universe Is Math?

S9 E2 / 17m 33s

Quantum phenomena have no subjective qualities and have questionable physicality. They seem to be completely describable by only numbers, and their behavior precisely defined by equations. In a sense, the quantum world is made of math. So does that mean the universe is made of math too? If you believe the Mathematical Universe Hypothesis then yes. And so are you.

What If Alien Life Were Silcon-Based?

S9 E3 / 14m 47s

Life as we know it is carbon-based, but does it have to be this way? There’s another element on the periodic table that shares some of the key properties of carbon but is far more abundant on most planets. I’m talking about silicon. So is there silicon-based life out there?

How Does the Earth Really Move Through The Galaxy?

S9 E4 / 16m 29s

Perhaps you’ve seen videos of how the planets of the solar system move through the universe in this cool helix. Not only are these misleading, but the Earth’s real motion - YOUR motion through the universe, is way more complicated and way more interesting.

How Does The Nucleus Hold Together?

S9 E5 / 14m 28s

Two protons next to each other in an atomic nucleus are repelling each other electromagnetically with enough force to lift a medium-sized labradoodle off the ground. Release this energy and you have a nuclear explosion. So how does it all hold together? Nuclei are held together by a quirk of nature, without which we would have no complex atoms, no chemistry, and certainly no labradoodles.

Are Space and Time Real?

S9 E6 / 18m 58s

Physics progresses by breaking our intuitions, but we’re now at a point where further progress may require us to do away with the most intuitive and seemingly fundamental concepts of all—space and time.

What’s Your Brain’s Role in Creating Space & Time?

S9 E7 / 16m 28s

Physics is the business of figuring out the structure of the world. So are our brains. But sometimes physics comes to conclusions that are in direct conflict with concepts fundamental to our minds, such as the realness of space and time. How do we tell who’s correct? Are time and space objective realities or human-invented concepts?

How Much Of The Universe Can Humanity Ever See?

S9 E9 / 16m 49s

There’s an absolute limit to our access to the universe beyond our own galaxy. So we’re going to figure out the absolute limit of our future view of the universe, and of the universe’s ability to influence us.

How Far Beyond Earth Could Humanity Spread?

S9 E10 / 15m 57s

Future generations may one day explore the cosmos and even settle entire other galaxies. But there is a hard limit to how much of the universe we can expand into. So, how big can humanity get?

New Discovery About Supermassive Black Holes Explained!

S9 E11 / 13m 25s

Astrophysicists have discovered a black hole that for millions of years has been blasting vast particle beams in opposite directions across the sky. And has recently swiveled to point its one of these jets directly at us.

Fermions Vs. Bosons Explained with Statistical Mechanics!

S9 E12 / 15m 51s

If I roll a pair of dice and you get to bet on one number, what do you choose? The smart choice is 7 because there are more ways for 2 dice to come up 7 than any other number. Well, it turns out that you can apply the same logic to predicting the behavior of the universe.

Could LIGO Find Massive Alien Spaceships?

S9 E13 / 16m 42s

The gravitational wave detector LIGO has made hugely important discoveries. But what else might be hiding in the ripples’ of spacetime? Oh, I know: how about the gravitational wakes caused by planet-sized alien spacecraft accelerating to near light speed.

Is 'Perpetual Motion' Possible with Superfluids?

S9 E14 / 16m

The weird rules of quantum mechanics lead to all sorts of bizarre phenomena on tiny scales— particles teleporting through walls or being in multiple places at once or simultaneously existing and not. Shame all this magical behavior doesn’t happen on scales large enough for us to see. Except that there is a way for us to see large-scale quantum weirdness, and that’s Bose-Einstein Condensates.

Could We Move Planet Earth Across the Universe?

S9 E15 / 12m 14s

Interstellar travel is horrible and deadly. Much safer to stay on here Earth with our gloriously habitable biosphere, protective magnetic field, and endless energy from the Sun. But what if we could turn our entire solar system into a spaceship and drive the Sun itself around the galaxy? Well, I don't know if we definitely can, but we might not not be able to.

What Supernova Distance Would Trigger Mass Extinction?

S9 E16 / 15m 16s

The deaths of massive stars results in one of the most beautiful and violent events in the universe: the supernova. But if these explosions occur too close to Earth their radiation can impact life and even trigger mass extinctions.

Did AI Prove Our Proton Model Wrong?

S9 E17 / 16m 24s

The humble proton may seem simple enough, and they’re certainly common. And protons are each made of three up or down quarks. Simple stuff, right? All except for that last part. Protons are actually made of many, many quarks that happen to look like three only when we look at them in a particular way. And even then, sometimes they’re made of 5 quarks - including the charm quark.

Does Axionic Dark Matter Bind Galaxies Together?

S9 E18 / 14m 39s

Quantum mechanics is our best theory of the fundamental nature of reality, but it's usually only distinguishable from familiar classical mechanics on the smallest scales. But it’s also possible that our entire galaxy is filled with a reverberating quantum mechanical wave that literally holds the galaxy together—and in fact explains all the dark matter that we see across the universe.

What If The Speed of Light is Not Constant?

S9 E19 / 15m 5s

One of the most fundamental physics facts is that the speed of light in a vacuum is constant for all observers. But can we really be sure? In fact, variable speed of light theories have long been used to try to explain everything from dark energy to gravity itself. Let’s explore how constant this fundamental constant really is.

Was the Gravitational Wave Background Finally Discovered?!?

S9 E20 / 15m 51s

A few weeks ago a large team of gravitational wave astronomers announced something pretty wild - pervasive ripples in the fabric of space time detected by the signals from rapidly spinning cores of dead stars in our galactic neighborhood. In other words, the gravitational wave background has probably been detected using a pulsar timing array.

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